package com.yoso.shop.interfaces.controller.user;

import io.swagger.annotations.Api;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

/**
 * @author yuluo
 * @date 2021-06-29 9:20
 */
@RestController("/checkcode")
@Api(tags = "验证码")
public class CheckCodeController {
    @GetMapping("/check")
    public void check(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("checkCodeServlet.check");
            int width=200;
            int height=69;
            BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
           //生成对应宽高的初始图片
            String randomText = VerifyCode.drawRandomText(width,height,verifyImg);
           //单独的一个类方法，出于代码复用考虑，进行了封装。
             //功能是生成验证码字符并加上噪点，干扰线，返回值为验证码字符
            req.getSession().setAttribute("verifyCode", randomText);
        //必须设置响应内容类型为图片，否则前台不识别
            resp.setContentType("image/png");
        //获取文件输出流
            OutputStream os = resp.getOutputStream();
        //输出图片流
            ImageIO.write(verifyImg,"png",os);
            os.flush();
            os.close();//关闭流
    }


    /**
     * 对图片进行处理的类和方法
     */
    public static class VerifyCode {
        @SuppressWarnings("AlibabaUndefineMagicConstant")
        public static  String drawRandomText(int width, int height, BufferedImage verifyImg) {
            Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();
            //设置画笔颜色-验证码背景色
            graphics.setColor(Color.WHITE);
            //填充背景
            graphics.fillRect(0, 0, width, height);
            graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));
            //数字和字母的组合
            String baseNumLetter= "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
            StringBuffer sBuffer = new StringBuffer();
            //旋转原点的 x 坐标
            int x = 10;
            String ch = "";
            Random random = new Random();
            for(int i = 0;i < 4;i++){
                graphics.setColor(getRandomColor());
                //设置字体旋转角度
                int degree = random.nextInt() % 30;  //角度小于30度
                int dot = random.nextInt(baseNumLetter.length());
                ch = baseNumLetter.charAt(dot) + "";
                sBuffer.append(ch);
                //正向旋转
                graphics.rotate(degree * Math.PI / 180, x, 45);
                graphics.drawString(ch, x, 45);
                //反向旋转
                graphics.rotate(-degree * Math.PI / 180, x, 45);
                x += 48;
            }
            //画干扰线
            for (int i = 0; i <6; i++) {
                // 设置随机颜色
                graphics.setColor(getRandomColor());
                // 随机画线
                graphics.drawLine(random.nextInt(width), random.nextInt(height),
                        random.nextInt(width), random.nextInt(height));
            }
            //添加噪点
            for(int i=0;i<30;i++){
                int x1 = random.nextInt(width);
                int y1 = random.nextInt(height);
                graphics.setColor(getRandomColor());
                graphics.fillRect(x1, y1, 2,2);
            }
            return sBuffer.toString();
        }
        /**
         * 随机取色
         */
        private static Color getRandomColor() {
            Random ran = new Random();
            Color color = new Color(ran.nextInt(256),
                    ran.nextInt(256), ran.nextInt(256));
            return color;
        }
    }
}
